Energy Supply Capacity Research Articles

Специфічні характеристики функціонального забезпечення спеціальнoї роботоздатності веслувальників на байдарках і каное

The article considers the specific characteristics of special work capacity functional support, which are formed depending on the structure of competitive activity and individual capabilities of athletes.Objective. To substantiate the possibilities of evaluation and interpretation of quantitative and qualitative characteristics of special work capacity functional support in athletes of cyclic sports events (on the example of kayaking).Methods. Oxycon mobile gas analyzer (jaeger), Polar sports tester with HR telemetry under loads and HR analyzer for computer data processing, laboratory complex for blood lactate determination Biosen S.line lab + for registration of indices of special work capacity and functionality of rowers were used. The Dansprint rowing ergometer was used to standardize the measurement of special work capacity.Results. It is shown that the implementation of the structure of competitive activity functional support is influenced by the individual type of reactivity to intense training and competitive loads, the ability to develop individual limit response levels, to maintain them in a stable state and the development of fatigue. The assessment of specific indices of special work capacity functional support is based on an integrated evaluation of aerobic energy supply capacity, based on the generalized characteristics of absolute and relative indices of maximum O2 consumption. The ability to rationally use aerobic reserve at different competitive distances is assessed on the basis of comparative analysis of power and capacity of anaerobic energy supply, the ability to realize aerobic power in conditions of high blood lactate level, the rate of lactate release into the blood during high intensity work.

Grid-Tied Distributed Generation Systems to Sustain the Smart Grid Transformation: Tariff Analysis and Generation Sharing

In this paper a novel model is being proposed and considered by ENEL—the largest electric utility in Chile—and analyzed thoroughly, whereby electric power control and energy management for a 60-apartments’ residential building is presented as an example of the utility’s green energy program, part of its Smart Grid Transformation plan to install grid-tied distributed generation (DG) systems, namely microgrids, with solar generation and energy storage in Santiago, Chile. The particular tariffs scheme analysis shown is part of the overall projected tentative benefits of adopting the new scheme, which will require the utility’s customers to adapt their consumption behavior to the limited supply of renewable energy by changing energy consumption habits and schedules in a way that maximizes the capacity and efficiency of the grid-tied microgrid with energy storage. The change in behavior entails rescheduling power consumption to hours where the energy supply capacity in the DG system is higher and price is lower as well as curtailing their power needs in certain hourly blocks so as to maximize DG system’s efficiency and supply capacity. Nevertheless, the latter presents a problem under the perspective of ENEL’s renewable energy sources (RES) integration plan with the electric utility’s grid supply, which, up until now and due to current electric tariffs law, has not had a clear solution. Under said scenario, a set of strategies based on energy homeostasis principles for the coordination and control of the electricity supply versus customers’ demand has been devised and tested. These strategies which consider various scenarios to conform to grid flexibility requirements by ENEL, have been adapted for the specific needs of these types of customers while considering the particular infrastructure of the network. Thus, the microgrid adjusts itself to the grid in order to complement the grid supply while seeking to maximize green supply capacity and operational efficiency, wherein the different energy users and their energy consumption profiles play a crucial role as “active loads”, being able to respond and adapt to the needs of the grid-connected microgrid while enjoying economic benefits. Simulation results are presented under different tariff options, system’s capacity and energy storage alternatives, in order to compare the proposed strategies with the actual case of traditional grid’s electricity distribution service, where no green energy is present. The results show the advantage of the proposed tariffs scheme, along with power control and energy management strategies for the integration of distributed power generation within ENEL’s Smart Grid Transformation in Chile.

Exploring high-penetration electric vehicles impact on urban power grid based on voltage stability analysis

Electric vehicles (EVs) have received significant attention in recent years. The high penetration of EVs increased the charging load in the distribution network, which has an enormous impact on “transportation and power grid” coupled energy networks. This paper developed the models and methods to evaluate the capacity of electrical energy supply based on voltage stability in the worst charging case scenario, under the existing coupled network. An optimization method with transportation network constraints is proposed to find the worst charging case scenario. In addition, the mobility of EVs is considered to calculate the load margin and the maximum number of EVs charging that a given grid can support in the critical situation. The method and model are simulated by test cases, which provide a perspective for realizing the EVs integration capacity limitation in urban areas considering the coupling relationship between transportation and power grids. Finally, the impact of charging location and route choice in the voltage margin limitation is emphasized.

Multi-mode analysis of a CO2-based combined refrigeration and power cycle for engine waste heat recovery

To realize the adjustable allocation of refrigeration and power in a combined refrigeration and power cycle, this study proposes a multi-mode cycle using CO2 as the working fluid. A refrigerated truck is selected as the research objective, the refrigeration demand and power demands of which vary frequently with different transportation conditions. The proposed system is driven by the exhaust gas of the main diesel engine and can replace the original refrigerator and related small-scale diesel engine. Three operating modes can be realized for different energy demands: full refrigeration output, combined refrigeration and power output, and full power output. The results indicate that the proposed system exhibits considerable potential for energy saving and diversified energy supply capacity. Following optimization of the configuration and parameters, the proposed energy solution (engine + proposed system) under the mode of combined refrigeration and power output can achieve a 2.9% fuel saving and 4.8% power increase simultaneously versus the original energy solution (engine + refrigerator) under refrigeration condition, 3.4% fuel saving and 1.6% power increase simultaneously under freezing conditions. The fuel economy is correspondingly improved 7.4% and 4.9%. Moreover, the proposed method can provide greater refrigeration and power capacities under the full refrigeration output and full power output modes.

Graphene oxide quantum dot exposure induces abnormalities in locomotor activities and mechanisms in zebrafish (Danio rerio).

Graphene oxide quantum dots (GOQDs) have broad applications such as bioimaging and drug delivery, among others, even expanding into the aquatic environment. However, reports on the adverse effects of GOQDs on fish development are limited. In this study, we exposed zebrafish embryos to GOQDs for 7 days after fertilization and found that GOQDs exposure at low concentrations (12.5, 25, 50 or 100 μg/L) decreased the total distance and the mean velocity of larvae movement. Additionally, the GOQDs significantly reduced the enzyme activity related to energy supply and locomotor capacity, including Ca2+ -ATPase in the 12.5, 25, 50 and 100 μg/L GOQDs groups and Na+ /K+ -ATPase in the 25 and 50 μg/L GOQDs groups. Moreover, GOQD exposure altered the mRNA expression of genes involved in energy supply and calcium transport. The levels of the atp2a2b, atp2a1, and cacna1sb genes were significantly downregulated in the 25, 50 and 100 μg/L GOQDs groups, and ryr3 expression was significantly reduced in the 25 and 50 μg/L GOQDs groups. The expression level of cacna1c was significantly upregulated in the 50 and 100 μg/L GOQDs groups. In summary, GOQD exposure induced a decrease in locomotor capacity in zebrafish, which may be due to the reduction of Ca2+ -ATPase and Na+ /K+ -ATPase activity levels, and dysregulated expression of the genes involved in energy metabolism and calcium transport. Our study provides novel insight into the effects of GOQDs on the embryonic development of fish, which will be useful for the development of environment-friendly GOQDs that reduce the potential hazard to aquatic species.

Comparison of different crop residue-based technologies for their energy production and air pollutant emission

Crop residue (CR) based-technology has several benefits, including renewable energy production and improvement in the environment and waste biomass management. However, the quantitative assessment of different CR based-technologies in terms of these benefits is limited. In this study, three typical CR-based technologies, CR biochar (CR-BC), CR direct-fired power (CR-DFP), and CR briquette biofuel (CR-BB), were assessed in terms of energy- and environment-related performances using a mixed-unit input-output life cycle assessment method. The results indicated that CR-BB performed better in energy production and air pollution mitigation than the other two technologies. Energy conversion efficiency was suggested as a key factor in determining the potentials of bioenergy production and environmental improvement. Furthermore, based on the energy demand from the Chinese agricultural sector and CR supply in 2012, the energy supply capacity (ESI) of CR-BC, CR-DFP, and CR-BB was estimated to be 24.3, 2.89, and 53.0, respectively, and their total greenhouse gas (GHG) reduction potential (TRGHG) was estimated to be 1.41 × 106, 4.81 × 106, and 1.68 × 106 t CO2e (CO2 equivalent), respectively. Overall, the CR-DFP and CR-BC are recommended for the high-value utilization of CR resources. The findings of this study could provide a basis for the development of CR-based technologies and CR management policy.

Comparative Proteomics of Salt-Tolerant and Salt-Sensitive Maize Inbred Lines to Reveal the Molecular Mechanism of Salt Tolerance.

Salt stress is one of the key abiotic stresses that causes great loss of yield and serious decrease in quality in maize (Zea mays L.). Therefore, it is very important to reveal the molecular mechanism of salt tolerance in maize. To acknowledge the molecular mechanisms underlying maize salt tolerance, two maize inbred lines, including salt-tolerant 8723 and salt-sensitive P138, were used in this study. Comparative proteomics of seedling roots from two maize inbred lines under 180 mM salt stress for 10 days were performed by the isobaric tags for relative and absolute quantitation (iTRAQ) approach. A total of 1056 differentially expressed proteins (DEPs) were identified. In total, 626 DEPs were identified in line 8723 under salt stress, among them, 378 up-regulated and 248 down-regulated. There were 473 DEPs identified in P138, of which 212 were up-regulated and 261 were down-regulated. Venn diagram analysis showed that 17 DEPs were up-regulated and 12 DEPs were down-regulated in the two inbred lines. In addition, 8 DEPs were up-regulated in line 8723 but down-regulated in P138, 6 DEPs were down-regulated in line 8723 but up-regulated in P138. In salt-stressed 8723, the DEPs were primarily associated with phenylpropanoid biosynthesis, starch and sucrose metabolism, and the mitogen-activated protein kinase (MAPK) signaling pathway. Intriguingly, the DEPs were only associated with the nitrogen metabolism pathway in P138. Compared to P138, the root response to salt stress in 8723 could maintain stronger water retention capacity, osmotic regulation ability, synergistic effects of antioxidant enzymes, energy supply capacity, signal transduction, ammonia detoxification ability, lipid metabolism, and nucleic acid synthesis. Based on the proteome sequencing information, changes of 8 DEPs abundance were related to the corresponding mRNA levels by quantitative real-time PCR (qRT-PCR). Our results from this study may elucidate some details of salt tolerance mechanisms and salt tolerance breeding of maize.

Energy use and emissions scenarios for transport to gauge progress toward national commitments

To achieve the mitigation targets discussed under the Paris Agreement, countries must develop studies that not only estimate baselines based on historical data of greenhouse gas (GHG) emissions and energy use, but that also project them considering different levels of ambition and political commitment. This study aims to develop and model scenarios of energy use and GHG emissions from the transport sector until 2030, considering the Brazilian Nationally Determined Contribution (NDC). Three scenarios were developed based on different political commitment. The method is based on a bottom-up approach, requiring multi-sectoral collaborative efforts to not only explain the direct energy use, but also balance the transportation activity and energy between the transport modes, justifying each case in terms of development stage and energy supply capacity. Here, transport sector has been further split up into the highest sector level detail available. At the maximum, GHG emissions could be reduced by 15% (29 Mt CO2e), achieved in scenario 3, whilst there are increases on emissions in scenario 2 (5% or 10 Mt CO2e) and scenario 1 (21% or 42 Mt CO2e). It implies that Brazil has the potential to ratchet up the mitigation targets discussed under the Paris Agreement of the UNFCCC.

Hollow nickel-cobalt-manganese hydroxide polyhedra via MOF templates for high-performance quasi-solid-state supercapacitor

Constructing high specific area and porous micro-nano frameworks is suitable for fast electrons/ions transport, which motivates us to design hollow polyhedra with multi-order structure. However, the synthesis route of hollow polyhedra is still restricted due largely to the complexity and high cost. Herein, the finding in rational design and one-pot hydrothermal synthesis of porous hollow nickel-cobalt-manganese hydroxide (NiCoMn-OH) polyhedra is reported, using zeolitic imidazolate framework-67 (ZIF-67) as the templates. The ultrathin edge-to-face stacking nanosheets construct a three-dimensional multi-order hollow polyhedral structure with internal nanoporous channels, which can stimulate electron/ion transfer. Toward the application in supercapacitor, the NiCoMn-OH electrode presented superior capacitance performance (1654.5 F g−1 at 1 A g−1) and excellent rate performance (58.5% retention at 30 A g−1) in a three electrode alkaline system. Moreover, the quasi-solid-state NiCoMn-OH//AC device was also fabricated, exhibiting excellent capacitance of 121.5 F g−1 at 1 A g−1, high energy density of 43.2 Wh kg−1 at a power density of 0.79 kW kg−1, and outstanding capacitance retention (100% retention after 10,000 cycles). Also, the suitable energy supply capacity of NiCoMn-OH electrode was further validated, via utilizing two quasi-solid-state NiCoMn-OH//AC devices to trigger light-emitting diode (LED) bulbs.

Design of a Functionalized Carbon Cloth Substrate for a Ni and Co-Based High-Performance Supercapacitor

Depressed reaction kinetics due to the electrochemical properties of transition metal materials themselves and a discordant coexistence relationship between substrates and these kinds materials remain major problems in developing high-performance supercapacitors (SCs). Here, a functionalized N, P dual-doped porous carbon cloth (NPPCC) substrate is designed using cotton spinning cloth as the original material, and the following NPPCC-supported Ni and Co bimetallic sulfide (NPPCC-BS) is applied to construct an SC. The porous carbon networks with structural defects and heteroatom doping exhibited in such a novel substrate are beneficial to not only robust and well-conditioned growth of active materials but also improved interface interrelation, thereby resulting in enhanced reaction kinetics of the hybrid electrode via strong coupling effect and stable combination between substrate and active materials. Accordingly, the NPPCC-BS electrode as positive electrode is fabricated into an all-solid-state asymmetric SC device; this device delivers high energy storage and supply capacity (45.8 Wh kg–1 at 15.7 kW kg–1) and an excellent long-term cycling life (88.6% capacity retention after 15000 cycles).

Energy and carbon intensity: A study on the cross-country industrial shift from China to India and SE Asia

The potential relocation of various industrial sectors from China to India and countries of the SE Asian region presents low cost opportunities for manufacturers, but also risks rising for energy demand and CO2 emissions. A cross-country shift of industrial output would present challenges for controlling emissions since India and SE Asian countries present higher industrial emissions intensity than China. We find that although there is a convergence in emissions intensity in the machinery manufacturing and paper and pulp industries, there are significant variations in all other industrial sectors. Indian emissions intensity is double that of China in the iron and steel and textile and leather industries and almost triple in the cement industry; Indonesian emissions intensity is almost double that of China in the non-metallic minerals and textile and leather industries and 50% higher in the chemical and petrochemical industry. We demonstrate that the expected higher emissions are driven by both a higher carbon fuel mix intensity in the recipient countries and higher energy intensity in their industrial activities. While industrial relocation could benefit certain countries financially, it would impose considerable threats to their energy supply security and capacity to comply with their Paris Agreement commitments.

Indicators of Body Reserve Opportunities for Young Gymnasts as One of the Factors for Successful Development of Initial Specialized Training

Background. The article deals with the problem of selection in gymnastics and the reasons why it is necessary to research that. Artistic gymnastics carries the heaviest losses on the initial stages of specialized training, which explains the lack of science-based regulatory requirements in the gymnastics system, allowing diagnosing, assessing and predicting the development of the main indicators of physical condition and fitness of athletes in complex.Research aim was to develop additional criteria of young gymnasts’ selection at the initial stage of specialized training on the basis of the indicators of human body reserve opportunities.Methods. Experimental work was carried out with gymnasts aged 9 years (n = 15) and 10 years (n = 16) in the research laboratory of Povolzhskaya State Academy of Physical Culture, Sport and Tourism and sports complex “Yar Chally” in Naberezhnye Chelny, Republic of Tatarstan (Russia).Results. Gymnasts aged 9–10 years had a harmonious type of power supply of the body: more gymnasts had aerobic-anaerobic type of muscular activity power supply. Gymnasts who qualified in the obligatory program of category 3 on pommel horse equally represented only the second and the third biological groups.The results of correlation analysis suggest that for gymnasts aged 9 years, the most significant factors affecting their special physical and technical fitness included aerobic capacity source of muscle activity energy supply and general metabolic capacity and for gymnasts aged 10 years – capacity and anaerobic power glycolytic sources of energy and muscular activity.Discussion and conclusions. Obtained information on the preferred for gymnastics bioenergy groups can help coaches in predicting abilities of young gymnasts.Keywords: sportspeople, gymnasts, selection, model descriptions, indicators of reserve opportunities.

Optimal operation of hybrid PV-battery system considering grid scheduled blackouts and battery lifetime

In many developing countries where the energy supply capacity is less than the demand, energy companies distribute the available power according to a specific time schedule, leading to grid scheduled blackouts (GSBs) for the costumers. A suitable way to solve this problem for residential loads is to install a combined photovoltaic (PV) and battery storage system as a replacement of the grid during the blackout periods. However, it is well-known that the lifetime of battery storage will be considerably shortened, if it is not operated appropriately. This paper explores the potential benefits of applying economic model predictive control (EMPC) to optimize the operation of a hybrid PV-battery system to address the GSB problem. The aim of our control strategy is to cover the load as much as possible and meanwhile minimize the total cost of the energy consumed from the grid. In particular, the battery is operated in such a way that its lifetime will be prolonged. A comparison between different operation strategies for the system considering the seasonal variation in the load and the PV power generation is made. The results show that the proposed approach leads to a significant reduction of the total energy consumed from the grid while decreasing the curtailment of the generated power from the PV-array, and maximizing the battery lifetime.

Industrial Relocation and CO2 Emission Intensity: Focus on the Potential Cross-Country Shift from China to India and SE Asia

The potential relocation of various industrial sectors from China to India and countries of the SE Asian region presents low cost opportunities for manufacturers, but also risks rising energy demand and CO2 emissions. A cross-country shift of industrial output would present challenges for controlling emissions since India and SE Asian countries present higher industrial emissions intensity than China. We find that although there is a convergence in emissions intensity in the Machinery manufacturing and Paper and Pulp industries, there are significant variations in all other industrial sectors. Indian emissions are double that of China in the Iron and Steel and Textile and Leather industries and almost triple in the cement industry; Indonesian emissions are almost double those of China in the Non-Metallic Minerals and Textile and Leather industries and 50% higher in the Chemical and Petrochemical industry. We demonstrate that the expected higher emissions are driven by both a higher fuel mix carbon intensity in the new countries and a higher energy intensity in their industrial activities. While industrial relocation could benefit certain countries financially, it would impose considerable threats to their energy supply security and capacity to comply with their Paris Agreement commitments.

Influence of Tween-80 on the production and structure of water-insoluble curdlan from Agrobacterium sp.

In order to explore the mechanism by which Tween-80 enhances the production of curdlan produced by Agrobacterium sp., the effects of Tween-80 on the production and structure of curdlan and Agrobacterium sp. were evaluated. Maximum curdlan production (51.94g/L) was achieved when 16g/L Tween-80 was added at the beginning of the cell growth stage. The addition of Tween-80 at higher concentration inhibited cell growth. However, the addition of 16g/L Tween-80 enhanced the production of curdlan with a looser ultrastructure, significantly weakened the envelopment of curdlan on Agrobacterium sp., altered the fine structure of cell membrane, and increased the cell membrane permeability. Moreover, the efficiency of oxygen and mass transport, respiration intensity, UTP regeneration, ATP regeneration, activity of curdlan synthetase, capacity of stress response and energy supply of Agrobacterium sp. were all greatly improved by the addition of Tween-80. These findings demonstrate the mechanisms by which Tween-80 enhances curdlan production and provide a cheap and feasible approach to weaken the envelopment of water-insoluble polysaccharides on bacteria.

Energy-efficient strategies for wireless sensor networks

Design of large scale wireless sensor networks WSN has become cost effective with the advances in inexpensive sensor technology and wireless communications and attracts the attention of a wide range of applications such as health and environmental monitoring and battlefields surveillance. Wireless Sensor Networks (WSNs) consists of huge number of Sensor Nodes (SNs) with sensing, communication and processing capabilities. SNs have limited energy supply, storage and computational capacity. In recent years energy efficient computation is a major concern in WSN. The critical aspects include reduction in the energy consumption of SNs so that the network lifetime can be extended to reasonable times. For this purpose many novel innovative techniques based on energy efficient computation have been proposed. In this paper, we present a brief analysis on energy efficient computation protocols. We have also presented a comparison of these protocols The main challenge in the design of wireless sensor networks is the limited battery power of the sensors and the difficulty of replacing and/or recharging these batteries due to the nature of the monitoring field and cost to ease this problem it is necessary that the sensors be densely deployed and appropriate protocols be designed in order to identify this redundancy while maximizing the lifetime of the network. Several protocols have been proposed in the literature with a goal to save the sensors energy. All those proposed algorithms aim to design energy efficient protocol for WSN. However these protocols consider the various issues of WSN separately.

Mechanical and electromyographic responses during the 3-min all-out test in competitive cyclists

While the 3-min all-out test is an ideal exercise paradigm to study muscle fatigue during dynamic whole-body exercise, so far it has been used mainly to provide insight into the bioenergetic determinants of performance. To shed some light into the development of peripheral muscle fatigue during the 3-min all-out test, we investigated the time course of muscle-fibre conduction velocity (MFCV). Twelve well-trained cyclists (23±3yrs) performed an incremental test, a 3-min all-out familiarization trial and a 3-min all-out test. Surface electromyographic signals were detected from the vastus lateralis muscle of the dominant limb. MFCV decreased with power output, though with a somewhat different time course, and the two parameters were strongly correlated (r=0.87; P<0.001). A modest decrease in MFCV (17.7±4.8%), probably due to the endurance characteristics of the subjects, may help explain why a relatively high power output (79±8% of the peak power output of the incremental test; 60±14% of the difference between this peak value and the gas exchange threshold) was still maintained at the end of the test. These findings suggest that muscle fatigue substantially affects performance in the 3-min all-out test, expanding on the traditional bioenergetic explanation that performance is limited by rate and capacity of energy supply.

Optimal Phase Change Temperature for Energy Storage Based on Fluctuating Loads in Building Cooling Heating and Power System

Abstract Natural gas driven Building Cooling Heating and Power (BCHP) system is encouraged to develop as small-scale energy supply system in recent year. Integrating Energy Storage System (TES) with tri-generation system can improve the energy efficiency and reduce the installed capacity for energy supply equipment. However, it has never been an easy task to reasonably design the TES-BCHP system, in terms of that it is hard to determine the suitable installed capacity of energy supply devices considering the fluctuating loads and the influence of TES. In this paper, a thermodynamic model of BCHP system with phase change material (PCM) energy storage is established. According to practical user loads and considering the correspondingly hourly changing flow rate in charge and discharge processes, a simplified method is proposed to determine the optimal phase change temperature for BCHP-TES, aiming to minimize the primary energy consumption of BCHP-TES system. An illustrative example shows that the optimal phase change temperature can be obtained for given loads. It also indicates that compared to infinite NTU for PCM-TES, the optimal phase change temperature will increase as well as the corresponding minimal primary energy consumption for finite NTU. This work is of great importance for PCM optimization of BCHP-TES system design.

Abstract 277: High Consistency in Left Ventricular 31P-MR Spectra in Rats in vivo Allows Follow-up Detection of Small Variations in Energy Status and Early Energy Defects

Introduction: Phosphorus magnetic resonance spectroscopy (31P-MRS) makes a unique and valuable contribution to understand how mitochondrial energy supply responds to ATP demand in beating hearts. Changes in PCr/ATP allow detecting energy dysbalance that often predict disease and mortality. However, MR techniques in vivo are challenged by tissue contamination and poor signal-to-noise (S/N) ratio, especially in hearts of rodent models. Methods: Here we optimized acquisition of localized cardiac 31P-MR spectra, obtained with a surface probe at 9.4T in vivo from left ventricle in control and SHR rats. MR spectra (192s) and short-axis cine-MRI frames were obtained during 9-weeks in sinus rhythm and during tachycardia induced by acute injection of isoproterenol (10μg/kg) at week 10. Results: Highly reproducible spectra with low S/N ratio helped demonstrating healthy PCr/ATP despite progressive ventricular hypertrophy in SHR rats. Isoproterenol induced similar tachycardia (425bpm ± 7) but higher drop in PCr/ATP (-17.1% vs. -4.7%, P&lt;0.05) associated with higher recovery time constant (23.9 vs. 7.3 min, P&lt;0.05). Discussion/Conclusion: Our results indicate that SHR rats maintain energy homeostasis during early development of pathology but present a blunted capacity of mitochondrial energy supply to respond to high ATP demand during strong ß-adrenergic activation of the myocardium. The optimization in localized 31P-NMR analysis offer exciting possibilities to better investigate primary precursors detection of cardiac failure in rodent models.

Developing a sustainable indoor air environment: Problems, considerations and suggestions

People spend over 80% of their lives in indoor environments. The indoor air environment is very important to human health, comfort and working efficiency. In the past two decades, China has experienced very rapid urbanization and economic development. Building areas have developed very rapidly during this period, and the quality of life has continuously improved. However, there are serious problems of the indoor air environment: (1) Building energy consumption continues to increase, which aggravates ambient air pollution. (2) People in regions without central space heating systems desire indoor heating in winter to be thermally comfortable. In such regions, use of the same techniques and standards as in northern China is unacceptable, owing to energy supply and environmental capacity limitations. (3) Air pollutants of outdoor or indoor origin degrade indoor air quality, which is harmful to human health. Taking several typical problems of the indoor air environment as examples, the present paper analyzes causes of those problems and indicates certain unsolved scientific and technical issues underlying them. Based on the literature and some of our own considerations, we assert that new approaches to such problems are needed to develop a sustainable indoor air environment that has “healthy, thermally comfortable/acceptable, and energy-efficient” features. Suggestions for further discussion are presented.